Engine ignition circuit with uniform leads

ABSTRACT

In an internal combustion engine having cylinders in line, the leads from the distributor to the spark plugs of all cylinders are measured and equalized in length of current travel by means of compensating coils preferably embedded in the distributor cap.

United States Patent [191 Allen ENGINE IGNITION CIRCUIT WITH UNIFORM LEADS Inventor: Kenneth A. Allen, 3912 Douglas Ave., Racine, Wis. 53402 Filed: Dec. 15, 1971 Appl. No.: 208,369

Related U.S. Application Data Continuation-impart of Ser. No. 1,618, Jan. 9, 1970, abandoned.

U.S. Cl 123/148 A Int. Cl. F02p 9/00 Field oiSearch 123/143 R, 143 A,

123/143 B, 1465, 146.5 A, 148 A [45] Aug. 28, 1973 [56] References Cited UNITED STATES PATENTS 3,342,168 9/1967 Burdette 123/148 A Primary Examiner-Laurence M. Goodridge Attorney-S. L. Wheeler [57] ABSTRACT In an internal combustion engine having cylinders in line, the leads firom the distributor to the spark plugs of all cylinders are measured and equalized in length of current travel by means of compensating coils preferably embedded in the distributor cap.

1 Claim, 3 Drawing Figures CIRCUIT WITH UNIFORM LEADS CROSS REFERENCE TO RELATED APPLICATION The present application is a continuation-in-part of my parent application Ser. No. 1,618, filed Jan. 9, 1970, and now abandoned.

BACKGROUND OF INVENTION Much irregularity of firing and slow or erratic acceleration of automobile engines, as well as formation of carbon in the cylinders has been found to be attributable to lack of uniformity in the leads from the distributor to the spark plugs. There are certain prior art patents that talk about uniform length of lead wires but the results sought seem to have been a matter of appearance rather than performance, since requisite uniformity could not be achieved externally of the distributor if the wires are parallel as taught by these patents.

Even in radial engines where one would suppose the ignition wires might tend to be of uniform length, they ENGINE IGNITION are not so in fact. I have checked this over a long period of years.

SUMMARY OF INVENTION Coils of wire of such length as to compensate for the shortness of external leads are preferably molded into the distributor cap, the coils being so related to the several leads that all are of equal length from the distributor contacts to the spark plugs controlled thereby. It is not known whether the observed results are attributable to a frequency tuning effect or whether they are attributable to a mere identity in length of travel of current.. Whatever the cause, the observed fact .is that when the several leads are identical in length an automobile engine which has been running roughly will run smoothly and carbon which has accumulated in certain cylinders more than others will be consumed and acceleration will be increased and fuel consumption decreased.

While it is preferred to use compensating coils as above described, I do not wish to limit the invention thereto, my broader claims being directed to the equalization of length in any manner.

BRIEF DESCRIPTION OF DRAWINGS FIG. I is a plan view showing a typical installation embodying the invention.

FIG. 2 is a fragmentary detail view in cross section on an enlarged scale through a portion of a distributor and distributor cap.

FIG. 3 is a diagrammatic view through a typical distributor cap.

DETAILED DESCRIPTION FIG. 2 shows a six-cylinder engine 10 having a distributor 12 with a central connection by means of lead 14 with a conventional coil 16.

As shown in FIG. 2, the wire 14 from the coil enters the center receptacle 18 of the distributor cap 20. A spring-pressed contact 22 electrically energized by wire 14 centrally engages the usual distributor head 24 on engine-driven shaft 26. In the FIG. 1 illustration, this shaft is assumed to be rotating clockwise.

In the course of this rotation, the distributor arm 28 passes successively beneath, and in close proximity to, the successive contacts 30, to which the high frequency current jumps and is ultimately conveyed to. the spark plugs.

Normally, the leads to the respective plugs would be in immediate direct connection with the several contacts 30. While various engines have various firing orders, the typical diagrammatic illustration herewith presented fires the several cylinders (starting at the front end near the fan 32) in the order of cylinders l, 5, 3, 6, 2, and 4. Obviously, the length of the lead from any given contact 30 to the respective spark plug will necessarily vary widely according to the location of the distributor and the distance from the distributor to the plug.

In the instant device as selected to disclose the ionvention, the lead 34 to the spark plug 36 of the first cylinder is considerably longer than any of the other leads. Accordingly, the conventional cap 38 at the end of lead 34 engages a receptable contact 40 within the distributor cap 20 which has a short and direct electrical connection at 42 to the terminal 30.

The spark plug 44 of cylinder 5, on the other hand, is relatively close to the distributor and accordingly its conventional lead 46 is quite short. In accordance with the present invention, the length of current travel between the distributor and the spark plug 44 is increased to match that of cylinder 1 by the provision of a compensating conductor coil 50 which is molded or otherwise housed in distributor cap 20 and has its ends connected between the receptacle 52 engaged by lead 46 and that terminal 30 which supplies current to such lead.

The external lead 54 which supplies cylinder 3 may be nearly the same in length as the lead 34 which supplies cylinder 1. I prefer that it be identical. Then the arrangement within the distributor cap is preferably adjusted to make the length identical.

The lead 56 which extends conventionally from the distributor to the spark plug serving cylinder 6 is the shortest of all and accordingly, the compensating coil 58 within the distributor cap 20 comprises a greater length of wire than any other. The lead 60 to spark plug of cylinder 2 is of moderate length and therefore the compensating coil 62 within the distributor cap 20 contains'relatively few turns. The relatively short external lead 64 from the distributor to the spark plug serving cyiinder 4 is relatively short and therefore the length of wire in the compensating coil 66 is relatively high.

The wire in the prefabricated wire harnesses in the ignition circuits of internal combustion engines should not only be of carefully predetermined length but these lengths should be taken into account in designing the compensating coils to be inserted into the distributor cap as herein disclosed.

The length of current travel from the source 16 to the distributor terminals can be ignored because it is inherently identical via conductor 14 to the central contact 22 and radially through arm 28 to successive distributor contacts 30.

1. An ignition circuit for an internal combustion engine comprising plural cylinders and having spark plugs, a source of ignition current, a distributor connected with said source and having terminals supplied with current for said plugs, said distributor further comprising means for sequentially connecting the terminals with said source for energizing said terminals, external leads from the distributor terminals to the several plugs, and compensating means for equalizing the total length of current travel between said terminals and the several plugs, said compensating means comprising coils constituting said equalizing means and being housed within a cap with which the distributor is provided and being connected within said cap to the said terminals. 

1. An ignition circuit for an internal combustion engine comprising plural cylinders and having spark plugs, a source of ignition current, a distributor connected with said source and having terminals supplied with current for said plugs, said distributor further comprising means for sequentially connecting the terminals with said source for energizing said terminals, external leads from the distributor terminals to the several plugs, and compensating means for equalizing the total length of current travel between said terminals and the several plugs, said compensating means comprising coils constituting said equalizing means and being housed within a cap with which the distributor is provided and being connected within said cap to the said terminals. 